Natural history collections: Unraveling communites past and a key to the future
It is increasingly recognized that natural history collections are key to understanding processes in past communities and to predicting future ecological trajectories. Patterns in paleocommunities are studied by definition in natural history collections, and can provide insight into both past communities and human impact on the environment. For species and communities of the Recent, there is a global explosion of computerized datasets that involve both observational and museum specimen data. Nevertheless, actual museum specimens are still key to studying biodiversity. Here we discuss some ecological patterns that emerge from the study of natural history collections in the eastern Mediterranean in terrestrial and marine environments in response to global change.
In the past decades the eastern Mediterranean Sea is undergoing extreme ecological changes. These changes involve accelerated rates of biological invasions from the Red Sea through the Suez Canal, coupled with climate change, overexploitation of marine resources, extreme habitat degradation, pollution, construction of coastal installations, and invasions through ballast waters. Natural history collections provide the record for these changes over past decades, involving not only the invasive species but also their ecto- and endoparasites, and allow us to analyze rates of invasion and to extrapolate projected changes.
In the terrestrial realm, natural history collections are used increasingly for studying climate change and its projected effects. Miceovolutionary change in body size of endotherms in the past century can provide insight into rates of adaptation that can be expected in response to climate change. However, studies of these responses have yielded conflicting results, possibly reflecting the effect of different selective pressures of global change. Traditionally natural history collections are used for mapping species distributions. They are now increasingly used to model projected changes in species distributions and species assemblages under different climate change scenarios, using a growing number of sophisticated models that allow the use of presence-only data. Use of such models can provide insight into conservation planning. We compare the predictions of such models with current open landscape conservation planning scenarios.
These examples and others highlight the significance of natural history collections as a dynamic archive of biodiversity. They also point out to the value of the actual specimens; much biological data (morphological change, parasite content, detailed taxonomic knowledge, changes in genetic structure, etc.) can be retrieved only from natural history collections.